CELLULAR COMPOSITION OF THE ISLETS OF LANGERHANS IN THE BULLFROG, RANA CATESBIANA

Abstract
The cellular composition of the islets of Langerhans was analysed in 10 normal bullfrogs. In spite of the either very low or zero blood sugar level in these amphibians it was possible to identify cells with the same staining properties as the A1 and A2 cells of other vertebrates. Each of the two types of A cells corresponded to no less than 25% of the total number of islet cells. The distinctly silver-positive A1 cells were characterized by a pronounced meta-chromasia, when stained with toluidine blue. Presence of cytoplasmic vacuoles of varying size was a conspicuous feature for the B cells in some of the bullfrogs.